Glass manufacturing apparatus are commonly used to form various glass products for example sheet glass for liquid crystal displays (LCDs), electrophoretic displays (EPD), organic light emitting diode displays (OLEDs), plasma display panels (PDPs), or other display applications. It is known to manufacture sheet glass by downwardly flowing molten glass over a forming wedge and using edge rollers to engage beads formed at opposite edge portions of a glass ribbon. One or more air bars are commonly used to support the glass ribbon as it traverses along a horizontal path. The air bar creates a cushion of air that facilitates support of the ribbon while avoiding physical contact with the air bar. As such, the pristine surfaces of the glass ribbon may be preserved since the air bar can ideally support the glass ribbon without contacting the glass ribbon. Even with the use of air bars, some procedures may frequently result in limited contact in an otherwise contactless support method. For instance, a coolant jet in a ribbon-severing procedure may consequently form a dimple in the glass surface that results in physical contact with the air bar. During such physical contact events, there is a desire to control the physical contact to avoid or minimize localized damage to the glass ribbon. There is also a desire to detect contact events in an effort to access consequent glass damage and/or modify the process to avoid future damage to the glass.
What is needed is and cost effective way to help detect physical contact events to enhance glass ribbon quality.